This invention relates to a caster and, more particularly, to improvements in a stopper unit for a caster.
A conventional caster is mounted, for example, at each leg or the like of a chair, a wagon deck, a part conveying box and so forth and is thus used to facilitate the movement thereof. The caster is conveniently provided to stop them at a predetermined position in a predetermined direction together with a stopper unit attached thereto for locking its wheel.
There are known at present conventional stopper units of various structures, most of which employ locking buttons and lock releasing buttons.
The stopper of this type is constructed to lock a stopper by pushing a locking button against the elastic force of a spring for urging the locking button and thereby engaging the stopper with a recess or the like formed on the periphery of a wheel and to release the lock of the stopper by pressing a lock releasing button to thereby disengage the spring and returning the stopper.
Since the locking button and the lock releasing button of the conventional stopper unit of the above described structure are generally operated to lock or release the lock of the stopper with a leg in a parallel alignment, they have difficulties such that the locking and the lock releasing operations are hard to carry out and that the selection of locking or lock releasing operation can be easily mistaken. Inasmuch as the locking button is retained in a pressed position in the stopper of this type structure, the conventional stopper further has such drawbacks and disadvantages that its connector to the spring tends to readily wear, the lock can be easily released with a slight external force or vibration applied thereto, or its production cost becomes expensive due to large number of parts.